Automated segmentation of vegetation structure units in a Mediterranean landscape

In Mediterranean regions, the combination of disturbances, life histories, plant regeneration traits, and microhabitat variability form highly heterogeneous vegetation mosaics which shift in space and time. Consequently, structure-based forest management is emerging as a superior alternative to management of vegetation formations in such areas. Delineation of management units in these areas is often based on manual interpretation of aerial imagery coupled with field surveys. Here, we propose an alternative approach that is based on segmentation of remotely sensed height and cover maps derived from light detection and ranging (LiDAR) imagery. A large suite of alternative segmentation maps was generated using multiresolution segmentation (MS) with different parameters, and an area-fit approach used to select the map that most successfully captured a reference set of structural units delineated manually. We assessed the feasibility of this approach in a nature reserve in northern Israel, compared the resulting map with a traditional vegetation formations map, and explored the performance of the segmentation algorithm under various parameter combinations. Pronounced differences between the structure and formation maps highlight the suitability of this approach as an alternative to the existing methods of delineating vegetation units in Mediterranean systems, and possibly in other systems as well.     

Soft Electronics Manufacturing Using Microcontact Printing

This work describes a microcontact printing (µCP) process for reproducible manufacturing of liquid gallium alloy–based soft and stretchable electronics. One of the leading approaches to create soft and stretchable electronics involves embedding liquid metals (LM) into an elastomer matrix. Although the advantages of liquid metal–based electronics have been well established, their mainstream adoption and commercialization necessitates development of precise and scalable manufacturing methods. To address this need, a scalable µCP process is presented that uses surface‐functionalized, reusable rigid, or deformable stamps to transfer eutectic gallium–indium (EGaIn) patterns onto elastomer substrates. A novel approach is developed to create the surface‐functionalized stamps, enabling selective transfer of LM to desired locations on a substrate without residues or electrical shorts. To address the critical needs of precise and reproducible positioning, alignment, and stamping force application, a high‐precision automated µCP system is designed. After describing the approach, the precision of stamps is evaluated and EGaIn features (as small as 15 µm line width), as well as electrical functionality of printed circuits with and without deformation, are fabricated. The presented process addresses many of the limitations associated with the alternative fabrication processes, and thus provides an effective approach for scalable fabrication of LM‐based soft and stretchable microelectronics.     

Medical students' attitudes regarding the use of life-sustaining treatments for themselves and for elderly persons

This study investigated students' wishes regarding the use of life-sustaining treatments (LST) in different health conditions compared with their evaluations of the wishes of elderly people, and with reports of a group of elderly people about themselves. Data were collected from two consecutive classes of first year medical students (n = 101), and a random sample of Israeli elderly aged 70+ (n = 987) who responded to fixed-choice questions regarding their will to live and wishes for three kinds of LST in a number of hypothetical illness conditions. The students were also asked to assess elderly's wishes. Students ranked the will to live of elderly persons significantly lower than their own. The elderly ranked their will to live significantly lower than did the students, but higher than the students assumed about them, indicating that although the will to live is weaker among older people, it is stronger than young persons believe. With regard to the use of LST, students believe that old people want less LST than themselves, but the elderly want even less LST than assumed by the students. The best predictors of students' wishes for themselves were fear of dying and religiosity. Fear of dying, the students' self-esteem and religiosity were the best predictors of their evaluations of the elderly's wishes. The results indicate that both the elderly and the students have a relatively strong will to live, but this desire is dependent on quality of life. The implications of this study for medical education are discussed.     

Controlled Assembly of Liquid Metal Inclusions as a General Approach for Multifunctional Composites

Soft composites that use droplets of gallium-based liquid metal (LM) as the dispersion phase have the potential for transformative impact in multifunctional material engineering. However, it is unclear whether percolation pathways of LM can support high electrical conductivity in a wide range of matrix materials. This issue is addressed through an approach to LM composite synthesis that focuses on the interrelated effects of matrix curing/solidification and droplet formation. The combined influence of LM concentration, particle size, and sedimentation is explored. By developing this approach, the functionalities that have been demonstrated with LM composites can be generalized to other matrix materials that impart additional functionality. Specifically, composites are synthesized using a biodegradable/reprocessable plastic (polycaprolactone), a hydrogel (poly(vinyl alcohol)), and a processable rubber (a styrene–ethylene–butylene–styrene derivative) to demonstrate wide applicability. This method enables synthesis of composites: i) with high stretchability and negligible electromechanical coupling ( > 600% strain); ii) with Joule-heated healing and reprocessability; iii) with electrical and mechanical self-healing; and iv) that can be printed. This approach to controlled assembly represents a widely applicable technique for creating new classes of LM composites with unprecedented multifunctionality.     

Thermal and viscoelastic behavior of polyurethane/polyvinylchloride blends

The potential of melt processing polymer blends to prepare damping materials was investigated. Binary and ternary blends of polyvinylchloride (PVC) with thermoplastic polyurethane elastomers (TPU) were studied. The soft segments of the polyurethanes for the first series were of the ether type and of the ester type for the second series of blends. A series of polymer blends were prepared by mechanical melt mixing and the apparent miscibility was evaluated from the thermal, dielectric, and dynamic mechanical behavior as well as from transmission electron microscopy. Some samples exhibited a single damping peak at low PVC content, indicating miscibility of the blends at the detection scale of the test method. The relationship between the properties and the morphology of the blends was studied.     

Modulation of Macrophage Fatty Acid Content and Composition by Exposure to Dyslipidemic Serum in Vitro

Macrophages in arterial walls accumulate lipids leading to the development of atherosclerotic plaques. However, mechanisms underlying macrophage lipid accumulation and foam cell formation are often studied without accounting for risk factors such as dyslipidemia. We investigated the effect of varying concentrations of triglyceride (TG) within physiological range on macrophage fatty acid (FA) accumulation and expression of cholesterol efflux proteins. Human monocytes were cultured in media supplemented with 10% sera containing low (0.7 mmol/L) to high (1.4 mmol/L) TG. The resulting macrophages were harvested after 10 days for analysis of FA content and composition and expression of genes involved in lipid metabolism. Exposure to higher TG and lower HDL concentrations in media increased macrophage lipid content. Macrophages exposed to higher TG had increased total FA content compared with controls (876 μg/mg protein vs. 652 μg/mg protein) and greater proportions of C16:0, C18:1 and C18:2. Macrophage expression of both ABCA1 and ABCG1 cholesterol efflux proteins were reduced when higher TG concentrations were present in the media. Expression of scavenger receptor CD36, involved in lipoprotein uptake, was also downregulated in macrophages exposed to higher TG. Culturing macrophages in conditions of higher versus lower TG influenced macrophage FA content and composition, and levels of regulatory proteins. Replicating in vitro levels of dyslipidemia encountered in vivo may provide an informative model for investigation of atherogenesis.     

Polyaniline-coated iron: studies on the dissolution and electrochemical activity as a function of pH

Polyaniline coatings were electrodeposited from an oxalic acid solution onto iron and their electrochemical activity and corrosion protection properties studied as a function of pH. It was found that the coating (emeraldine salt) had a limited effect on the corrosion protection of iron in acidic solutions. However, in an alkaline borate solution, where the conducting polyaniline was converted to the emeraldine base, the coating had a clear beneficial effect on the local breakdown of iron by chloride anions; much higher pitting potentials were recorded following a 2 h immersion period for the polyaniline-coated substrate relative to the uncoated electrode. Relatively small anions, such as acetates, nitrates and borates, were transported readily across the polymer interface. However, the emeraldine base inhibited the transport of the much larger ethylenediamine tetraacetate (EDTA) species to the iron interface, preventing complexation of the iron by EDTA.